I've been using my Microsoft TBO for about 7 years now, they're great. I've also used the Trackman, and equally great. The ball is a little smaller, and there's no Mouse4/Mouse5, but you're not throwing down some coin like you are with the Microsoft Trackball. I am the same way you are, I can't live without my back/forward history buttons. If you use a Mac though, the Intellimouse drivers for it are a little shotty. Usually the Button 4 and 5 work fine for a while until the Mac goes to sleep. Eventually they stop operating and I have to restart the service to get it to pick them back up. On Windows, it's been bullet proof. Not a single hiccup, I don't even need Intellimouse drivers, the PnP drivers built into XP pick it up.